1. Field of the Invention
The present invention relates to a semiconductor process, and more particularly, to a treatment method for a surface of a photoresist layer and a method for forming a patterned photoresist layer by using the treatment method.
2. Description of the Related Art
Toward a higher and higher degree of integration in the field of semiconductor technology, designs for circuit devices have to meet the trend in reducing sizes of devices. Currently, 90-nm semiconductor technology has been developed and applied in processes. One of the most essential processes in semiconductor technology is photolithographic process, which plays an important role in deciding critical dimensions of devices.
During photolithographic process, a patterned photoresist layer is formed by performing a exposure step and a development step for a photoresist layer. Due to the requirement of small dimensions, dimensions of the patterned photoresist become smaller, and consequently the profiles of the patterned photoresist layer cannot be easily maintained. Sometimes, collapses of the patterned photoresist layer may occur. Also, because of the requirement of small dimensions and components of the photoresist, when an etching process is performed, a patterned photoresist layer suffers high temperature from plasma to cause the patterned photoresist layer collapse.
FIG. 1 is a picture of a patterned photoresist layer created by a prior art photolithographic process of the 90-nm technology. Referring to FIG. 1, due to the reduction of the line width of the patterned photoresist layer, the profile of the patterned photoresist layer is distorted. In the subsequent etching process using the patterned photoresist layer as a mask will result in pattern distortions or undesired profiles on the film layer due to the distorted patterned photoresist layer.